WS8-1 WORKSHOP 8 RECTANGULAR SECTION CANTILEVER BEAM CAT509, Workshop 8, March 2002

WS8-2 CAT509, Workshop 8, March 2002

WS8-3 CAT509, Workshop 8, March inches 4000 lbs (2 ton) n Problem Description u Load case. WORKSHOP 8 – RECTANGULAR CANTILEVER BEAM Material: Heat Treated 4340 Steel Young Modulus = 29.0e6 psi Poisson Ratio =.266 Density =.284 lb_in3 Yield Strength = psi

WS8-4 CAT509, Workshop 8, March 2002 n Problem Description u Hand Calculations u Displacement: u Bending Stress u Horizontal shear stress WORKSHOP 8 – RECTANGULAR CANTILEVER BEAM

WS8-5 CAT509, Workshop 8, March 2002 n Suggested Exercise Steps 1. Create a new CATIA analysis document (.CATAnalysis). 2. Mesh globally with linear elements. 3. Apply a clamp restraint. 4. Apply a distributed force. 5. Compute the initial analysis. 6. Check global and local precision (animate deformation, adaptive boxes and extremas). 7. Change mesh to parabolic. 8. Compute the precise analysis. 9. Visualize final results. 10. Save the analysis document. WORKSHOP 8 – RECTANGULAR CANTILEVER BEAM

WS8-6 CAT509, Workshop 8, March 2002 Step 1. Create a new CATIA analysis document Steps: 1. Open the existing ws8rectangularBeam.C ATPart from the training directory. 2. Apply steel material properties to the part as required. 3. Launch the Generative Structural Analysis workbench. 4. Specify the Computations and Results storage locations as shown.

WS8-7 CAT509, Workshop 8, March 2002 Step 2. Mesh globally with linear elements Define the global finite element mesh properties. Steps: 1. Double Click the “OCTREE Tetrahedron Mesh.1:Pedal” representation in the features tree or the “Mesh” icon on the part. 2. Specify the recommended rough Global Size =.25”. 3. Specify the recommended Sag = 10% of Global Size. 4. Specify element type “Linear” (TE4, means 4 corner nodes tetrahedron) and is good for a rough analysis, select OK Linear TE4 Parabolic TE10

WS8-8 CAT509, Workshop 8, March 2002 Step 2. Mesh globally with linear elements Compute and visualize the mesh only Steps: 1. Select the compute icon and compute mesh only, select OK 2. Right click Finite element Model in the features tree then select Mesh Visualization. 3. Note the image that get added to the features tree

WS8-9 CAT509, Workshop 8, March 2002 Step 2. Mesh globally with linear elements Better visualize the mesh by turning off the material rendering. Steps: 1. From the menu select View, Render Style and Customize View. 2. Click the Facet box, select OK (this will turn off the Materials rendering). 3. This icon shows your customized view parameters. 4. The dynamic hidden line removal image shows only the outside elements

WS8-10 CAT509, Workshop 8, March 2002 Step 2. Mesh globally with linear elements Better visualize by shrinking the mesh elements. Steps: 1. Double click the Mesh object in the features tree. 2. Slide the Shrink Coefficient bar to 0.90%, select OK. 1 2

WS8-11 CAT509, Workshop 8, March 2002 Step 3. Apply a clamp restraint Steps: 1. Inactivate the Mesh image in the features tree by right clicking then select Image activate/deactivate. 2. Change your display mode to Shading with Edges. 3. Select the Clamp Restraint icon. 4. Select the face at the origin, select OK. 5. Note the Clamp object added to the features tree

WS8-12 CAT509, Workshop 8, March 2002 Step 3. Apply a clamp restraint Examine the details of what this clamp feature is doing at the nodes. Steps: 1. Re-compute Mesh only. 2. Display geometry with the Dynamic Hidden Line Removal icon. 3. Activate the Mesh image in the features tree by right clicking then select Image activate/deactivate. 4. Right click the Clamp.1 object in the features tree then select Restraint visualization on mesh

WS8-13 CAT509, Workshop 8, March 2002 Step 3. Apply a clamp restraint Further examine the details of what this clamp feature is doing at the nodes. Steps: 1. Double click the Mesh object in the features tree. 2. Select the Selections tab and Clamp.1 in the Fem Editor, select OK. 1 Symbol indicates clamped, or all 6 degrees of freedom restricted. 2

WS8-14 CAT509, Workshop 8, March 2002 Step 4. Apply a distributed force Steps: 1. Double click the Mesh object in the features tree. 2. Select the Selections tab and “All” in the Fem Editor, select OK.. 3. DeActivate the “Restraint symbol” and the “Mesh” image in the features tree by right clicking then select Image activate/deactivate. 4. Display geometry with the Dynamic Hidden Line Removal icon

WS8-15 CAT509, Workshop 8, March 2002 Step 4. Apply a distributed force Steps: 1. Select the Force icon. 2. Select end face as shown. 3. Enter lbs in the Z-direction, select OK

WS8-16 CAT509, Workshop 8, March 2002 Step 4. Apply a distributed force Examine the details of what this Distributed Force.1 feature is doing at the nodes. Steps: 1. Re-compute Mesh only. 2. Display geometry with the Wireframe (NHR) icon. 3. Activate the Mesh image in the features tree by right clicking then select Image activate/deactivate. 4. Right click Distributed Force.1 object in the features tree then select Restraint visualization on mesh

WS8-17 CAT509, Workshop 8, March 2002 Step 4. Apply a distributed force Further examine the details of what this Distributed Force.1 feature is doing at the nodes. Steps: 1. Double click the Mesh object in the features tree. 2. Select the Selections tab and Distributed Force.1 in the Fem Editor, select OK. 1 2

WS8-18 CAT509, Workshop 8, March 2002 Step 5. Compute the initial analysis Steps: 1. Double click the Mesh object in the features tree. 2. Select the Selections tab and “All” in the Fem Editor, select OK.. 3. DeActivate the “Distributed Force.1” and the “Mesh” image in the features tree by right clicking then select Image activate/deactivate. 4. Change your display mode to Shading with Edges

WS8-19 CAT509, Workshop 8, March 2002 Step 5. Compute the initial analysis Steps: 1. Select the Compute icon. 2. Compute All Objects defined, select OK. 3. Always be aware of these values, select Yes. Save often.

WS8-20 CAT509, Workshop 8, March 2002 Visualize the computation error map. Steps: 1. Select the Precision icon. 2. Select on the information icon. 3. Select the Estimated local error object in the features tree. Note the global estimated error rate is good (recommend max 20%). Step 6. Check global and local precision 1 4b 2 3

WS8-21 CAT509, Workshop 8, March 2002 Step 6. Check global and local precision 1 Find the global element with the highest estimated error. Steps: 1. Select the Search Image Extrema icon. 2. Select Global and 2 maximum extrema at most, select OK. 3. Right click the Global Maximum.1 object in the features tree then select Focus On. 2 3

WS8-22 CAT509, Workshop 8, March 2002 Step 6. Check global and local precision 1 2a Determine local error percentage (%). Steps: 1. Select the adaptivity box icon. 2. Select the “Select Extremum” button then Global Maximum.1 in the features tree to locate box. 3. Use the compass and green dots to locate and size box around meshed areas. 4. Since local error is above 10% try changing the mesh element to Parabolic. 2b 4 3

WS8-23 CAT509, Workshop 8, March 2002 Step 7. Change mesh to parabolic Redefine the global finite element mesh type. Steps: 1. Double Click the “OCTREE Tetrahedron Mesh.1” representation in the features tree or the “Mesh” icon centered on the part. 2. Change element type to Parabolic, select OK. 2 1

WS8-24 CAT509, Workshop 8, March 2002 Step 8. Compute the precise analysis Steps: 1. Select the Compute icon. 2. Compute All Objects defined, select OK. 3. Always be aware of these values, select Yes. Save often.

WS8-25 CAT509, Workshop 8, March 2002 Check how much the global estimated error has improved Steps: 1. Right click the Estimated local error object in the features tree then select Image Activate/DeActivate to activate the image. 2. Select on the information icon. 3. Select the Estimated local error object in the features tree. Note the global estimated error rate is very good. Step 8. Compute the precise analysis 1 2 3

WS8-26 CAT509, Workshop 8, March 2002 Step 8. Compute the precise analysis Check how much the local estimated error has improved. Steps: 1. Right click Extrema object in the features tree then select Local Update. 2. Double click the Adaptivity Box.1 object in the features tree. 3. Since local error is below 10% we have a precise model

WS8-27 CAT509, Workshop 8, March 2002 Step 9. Visualize final results Add the displacement image. Steps: 1. Put the adaptivity box into no show by right clicking Adaptivity Process in the features tree then select Hide/Show. 2. Select the displacement icon to add this image. 2 1

WS8-28 CAT509, Workshop 8, March 2002 Step 9. Visualize final results Find the element with maximum displacement. Steps: 1. Select the search image extrema icon then select Global and key in 2 Maximum extrema at most. 2. Right click Global Maximum.1 in the features tree then select Focus On. 1a 1b 2

WS8-29 CAT509, Workshop 8, March 2002 Step 9. Visualize final results Find x, y, z displacements for the element with maximum displacement. Steps: 1. Right click Global Maximum.1 in the features tree then select Hide/Show. 2. Double click Translational displacement vector in the features tree then select the filters tab. 3. By positioning the cursor on a displacement symbol the component values show relative to the current Filter. 2a 2b = V1 = X = V2 = Y = V3 = Z 3 1

WS8-30 CAT509, Workshop 8, March 2002 Step 9. Visualize final results Change the displacement image from symbols to Average-ISO Steps: 1. From the menu select View, Render Style then Customize View. 2. Click on the Materials box so we can render our image with solid colors. 3. Display customized view parameters. 4. Double click Translational displacement vector in the features tree then select the AVERAGE- ISO in the Visu tab a 4b

WS8-31 CAT509, Workshop 8, March 2002 Step 9. Visualize final results 1 Visualize Von Mises stress field patterns. Steps: 1. Select the Stress Von Mises icon. This automatically deactivates the Translational displacement image and activates the Von Mises image.

WS8-32 CAT509, Workshop 8, March 2002 Step 9. Visualize final results Find the element with maximum Von Mises Stress. Steps: 1. Select the search image extrema icon then select Global and key in 2 Maximum extrema at most. 2. Right click Global Maximum.1 in the features tree then select Focus On. 1a 1b 2

WS8-33 CAT509, Workshop 8, March 2002 Step 9. Visualize final results Find exact recommend design stress. Steps: 1. Right click Global Maximum.1 in the features tree then select Hide/Show. 2. Double click Von Mises Stress object in the features tree. Note you are looking at stress values averaged across elements. 3. Also by selecting the Filters tab notice the stress output is calculated at the nodes. 4. Select Iso/Fringe and select the ISO smooth box to turn it off select OK twice. 2a 1 3 2b 4

WS8-34 CAT509, Workshop 8, March 2002 Step 9. Visualize final results Find exact recommend design stress. Steps: 1. By positioning the cursor on a element the stress values show relative to the current Filter (in this case at the nodes). 2. The maximum extrema stress is uninfluenced by poisson effects yielding higher than expected stresses 3. The design stress is found at the intermediate nodes of the bottom elements – psi 2 1 3

WS8-35 CAT509, Workshop 8, March 2002 Step 9. Visualize final results Find horizontal shear stress. Steps: 1. Select the Principal Stress icon. This automatically deactivates the Von Mises stress image and activates the Principal Stress image. 2. Double click Stress principal tensor symbol object in the features tree. 3. Select the Criteria tab and then select MATRIX-COLUMN. 4. Select the Filters tab and with the arrow select the Col3 Component, select OK

WS8-36 CAT509, Workshop 8, March 2002 Step 9. Visualize final results Find horizontal shear stress. Hold the cursor on the tensor symbols will show the values. Hold the Ctrl key down to select multiple values. Steps: 1. Highest value should occur at the neutral axis. This model shows 3290 psi 2. Lowest value should occur on the outer edges. 1 2

WS8-37 CAT509, Workshop 8, March 2002 Step 9. Visualize final results Hand Calculations.25” Parabolic Global Mesh,.025” sag Global % Precision error Local % Precision error NA 1.25 % 2.93 % Error EstimateNA2.5e-7 Btu global Translational Displacement inch inch (Z - direction) Max Von Mises Stress72000 psi psi Horizontal Shear Stress3000 psi3290 psi n Conclusions u CATIA V5 GSA workbench is validated for a rectangular cantilever beam scenario. To be conservative, increase material strength to a minimum yield of psi for the described load case.

WS8-38 CAT509, Workshop 8, March 2002 Step 10. Save the analysis document Steps: 1. Select Save Management from the File menu. 2. Highlight document you want to save. 3. Select Save As to specify name and path, select, OK

WS8-39 CAT509, Workshop 8, March 2002 n List of Symbols and Definitions u Greek letters. ALL WORKSHOPS Angular acceleration (radians/sec/sec); included angle of beam curvature (degrees); form factor. Perpendicular deflection (in.), bending (b) or shear (s). Unit strain, elongation or contraction (in./in.) Unit shear strain (in./in.). Poisson’s ratio (aluminum =.346 usually, steel =.266 usually); unit shear force. Unit angular twist (radians/linear inch); included angle; angle of rotation. Normal stress, tensile or compressive (psi); strength (psi). Bending stress (psi). Yield strength (psi). Shear stress (psi); shear strength (psi). Angle of twist (radians; 1 radian = 57.3 degrees); angle of rotation (radians); slope of tapered beam; any specified angle.

WS8-40 CAT509, Workshop 8, March 2002 n List of Symbols and Definitions u Letters. ALL WORKSHOPS a = area of section where stress is desired or applied (in2) b = width of section (in) c = distance from neutral axis to extreme fiber (in) d = depth of section (in) e = eccentricity of applied load (in) f = force per linear inch (in) g = acceleration of gravity (386.4 inch/sec2) h = height (in) k = any specified constant or amplification factor m = mass n = distance of section’s neutral axis from ref axis (in) p = internal pressure (psi) r = radius (in); radius of gyration t = thickness of section (in) w = uniformly distributed load (lbs/linear inch) y = distance of area’s center of gravity to neutral axis of entire section (in) A = area (in2); total area of cross-section E = modulus of elasticity, tension (psi) F = total force (lbs); radial force (lbs) I = moment of inertia (in4) J = polar moment of inertia (in4) L = length of member (in) M = bending moment (in-lbs) P = concentrated load (lbs) Q = shear center R = reaction (lbs) S = section modulus (in3) = I/c T = torque or twisting moment (in-lbs V = vertical shear load (lbs) W = total load (lbs); weight (lbs) C.G. = center of gravity D.O.F = degrees of freedom N.A. = neutral axis